Gallium nitride materials include gallium nitride (GaN) and its alloys such as aluminum gallium nitride (AlGaN), indium gallium nitride (InGaN), and aluminum indium gallium nitride (AlInGaN). These materials are semiconductor compounds that have a relatively wide, direct bandgap which permits highly energetic electronic transitions to occur. Such electronic transitions can result in gallium nitride materials having a number of attractive properties including the ability to efficiently emit blue light, the ability to transmit signals at high frequency, and others. Accordingly, gallium nitride materials are being widely investigated in many microelectronic applications such as transistors, field emitters, and optoelectronic devices.
Despite the attractive properties noted above, a number of challenges exist in connection with developing gallium nitride material devices. For example, gallium nitride material devices can generate significant amounts of heat during use which can have adverse effects on the performance of devices. For instance, increased device temperature can result in lower carrier mobility, lower sheet charge density, lower effective saturation velocity, and higher leakage currents, effectively limiting the ability of the device to produce RF power. Accordingly, it can be advantageous to remove heat efficiently from a device to keep device temperatures below a desired limit.